diff options
Diffstat (limited to 'drivers/net/wireless/intel/ipw2x00/libipw_tx.c')
| -rw-r--r-- | drivers/net/wireless/intel/ipw2x00/libipw_tx.c | 536 |
1 files changed, 536 insertions, 0 deletions
diff --git a/drivers/net/wireless/intel/ipw2x00/libipw_tx.c b/drivers/net/wireless/intel/ipw2x00/libipw_tx.c new file mode 100644 index 000000000000..e8c039879b05 --- /dev/null +++ b/drivers/net/wireless/intel/ipw2x00/libipw_tx.c @@ -0,0 +1,536 @@ +/****************************************************************************** + + Copyright(c) 2003 - 2005 Intel Corporation. All rights reserved. + + This program is free software; you can redistribute it and/or modify it + under the terms of version 2 of the GNU General Public License as + published by the Free Software Foundation. + + This program is distributed in the hope that it will be useful, but WITHOUT + ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + more details. + + You should have received a copy of the GNU General Public License along with + this program; if not, write to the Free Software Foundation, Inc., 59 + Temple Place - Suite 330, Boston, MA 02111-1307, USA. + + The full GNU General Public License is included in this distribution in the + file called LICENSE. + + Contact Information: + Intel Linux Wireless <ilw@linux.intel.com> + Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497 + +******************************************************************************/ +#include <linux/compiler.h> +#include <linux/errno.h> +#include <linux/if_arp.h> +#include <linux/in6.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/proc_fs.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/tcp.h> +#include <linux/types.h> +#include <linux/wireless.h> +#include <linux/etherdevice.h> +#include <asm/uaccess.h> + +#include "libipw.h" + +/* + +802.11 Data Frame + + ,-------------------------------------------------------------------. +Bytes | 2 | 2 | 6 | 6 | 6 | 2 | 0..2312 | 4 | + |------|------|---------|---------|---------|------|---------|------| +Desc. | ctrl | dura | DA/RA | TA | SA | Sequ | Frame | fcs | + | | tion | (BSSID) | | | ence | data | | + `--------------------------------------------------| |------' +Total: 28 non-data bytes `----.----' + | + .- 'Frame data' expands, if WEP enabled, to <----------' + | + V + ,-----------------------. +Bytes | 4 | 0-2296 | 4 | + |-----|-----------|-----| +Desc. | IV | Encrypted | ICV | + | | Packet | | + `-----| |-----' + `-----.-----' + | + .- 'Encrypted Packet' expands to + | + V + ,---------------------------------------------------. +Bytes | 1 | 1 | 1 | 3 | 2 | 0-2304 | + |------|------|---------|----------|------|---------| +Desc. | SNAP | SNAP | Control |Eth Tunnel| Type | IP | + | DSAP | SSAP | | | | Packet | + | 0xAA | 0xAA |0x03 (UI)|0x00-00-F8| | | + `---------------------------------------------------- +Total: 8 non-data bytes + +802.3 Ethernet Data Frame + + ,-----------------------------------------. +Bytes | 6 | 6 | 2 | Variable | 4 | + |-------|-------|------|-----------|------| +Desc. | Dest. | Source| Type | IP Packet | fcs | + | MAC | MAC | | | | + `-----------------------------------------' +Total: 18 non-data bytes + +In the event that fragmentation is required, the incoming payload is split into +N parts of size ieee->fts. The first fragment contains the SNAP header and the +remaining packets are just data. + +If encryption is enabled, each fragment payload size is reduced by enough space +to add the prefix and postfix (IV and ICV totalling 8 bytes in the case of WEP) +So if you have 1500 bytes of payload with ieee->fts set to 500 without +encryption it will take 3 frames. With WEP it will take 4 frames as the +payload of each frame is reduced to 492 bytes. + +* SKB visualization +* +* ,- skb->data +* | +* | ETHERNET HEADER ,-<-- PAYLOAD +* | | 14 bytes from skb->data +* | 2 bytes for Type --> ,T. | (sizeof ethhdr) +* | | | | +* |,-Dest.--. ,--Src.---. | | | +* | 6 bytes| | 6 bytes | | | | +* v | | | | | | +* 0 | v 1 | v | v 2 +* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +* ^ | ^ | ^ | +* | | | | | | +* | | | | `T' <---- 2 bytes for Type +* | | | | +* | | '---SNAP--' <-------- 6 bytes for SNAP +* | | +* `-IV--' <-------------------- 4 bytes for IV (WEP) +* +* SNAP HEADER +* +*/ + +static u8 P802_1H_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0xf8 }; +static u8 RFC1042_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0x00 }; + +static int libipw_copy_snap(u8 * data, __be16 h_proto) +{ + struct libipw_snap_hdr *snap; + u8 *oui; + + snap = (struct libipw_snap_hdr *)data; + snap->dsap = 0xaa; + snap->ssap = 0xaa; + snap->ctrl = 0x03; + + if (h_proto == htons(ETH_P_AARP) || h_proto == htons(ETH_P_IPX)) + oui = P802_1H_OUI; + else + oui = RFC1042_OUI; + snap->oui[0] = oui[0]; + snap->oui[1] = oui[1]; + snap->oui[2] = oui[2]; + + memcpy(data + SNAP_SIZE, &h_proto, sizeof(u16)); + + return SNAP_SIZE + sizeof(u16); +} + +static int libipw_encrypt_fragment(struct libipw_device *ieee, + struct sk_buff *frag, int hdr_len) +{ + struct lib80211_crypt_data *crypt = + ieee->crypt_info.crypt[ieee->crypt_info.tx_keyidx]; + int res; + + if (crypt == NULL) + return -1; + + /* To encrypt, frame format is: + * IV (4 bytes), clear payload (including SNAP), ICV (4 bytes) */ + atomic_inc(&crypt->refcnt); + res = 0; + if (crypt->ops && crypt->ops->encrypt_mpdu) + res = crypt->ops->encrypt_mpdu(frag, hdr_len, crypt->priv); + + atomic_dec(&crypt->refcnt); + if (res < 0) { + printk(KERN_INFO "%s: Encryption failed: len=%d.\n", + ieee->dev->name, frag->len); + ieee->ieee_stats.tx_discards++; + return -1; + } + + return 0; +} + +void libipw_txb_free(struct libipw_txb *txb) +{ + int i; + if (unlikely(!txb)) + return; + for (i = 0; i < txb->nr_frags; i++) + if (txb->fragments[i]) + dev_kfree_skb_any(txb->fragments[i]); + kfree(txb); +} + +static struct libipw_txb *libipw_alloc_txb(int nr_frags, int txb_size, + int headroom, gfp_t gfp_mask) +{ + struct libipw_txb *txb; + int i; + txb = kmalloc(sizeof(struct libipw_txb) + (sizeof(u8 *) * nr_frags), + gfp_mask); + if (!txb) + return NULL; + + memset(txb, 0, sizeof(struct libipw_txb)); + txb->nr_frags = nr_frags; + txb->frag_size = txb_size; + + for (i = 0; i < nr_frags; i++) { + txb->fragments[i] = __dev_alloc_skb(txb_size + headroom, + gfp_mask); + if (unlikely(!txb->fragments[i])) { + i--; + break; + } + skb_reserve(txb->fragments[i], headroom); + } + if (unlikely(i != nr_frags)) { + while (i >= 0) + dev_kfree_skb_any(txb->fragments[i--]); + kfree(txb); + return NULL; + } + return txb; +} + +static int libipw_classify(struct sk_buff *skb) +{ + struct ethhdr *eth; + struct iphdr *ip; + + eth = (struct ethhdr *)skb->data; + if (eth->h_proto != htons(ETH_P_IP)) + return 0; + + ip = ip_hdr(skb); + switch (ip->tos & 0xfc) { + case 0x20: + return 2; + case 0x40: + return 1; + case 0x60: + return 3; + case 0x80: + return 4; + case 0xa0: + return 5; + case 0xc0: + return 6; + case 0xe0: + return 7; + default: + return 0; + } +} + +/* Incoming skb is converted to a txb which consists of + * a block of 802.11 fragment packets (stored as skbs) */ +netdev_tx_t libipw_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct libipw_device *ieee = netdev_priv(dev); + struct libipw_txb *txb = NULL; + struct libipw_hdr_3addrqos *frag_hdr; + int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size, + rts_required; + unsigned long flags; + int encrypt, host_encrypt, host_encrypt_msdu; + __be16 ether_type; + int bytes, fc, hdr_len; + struct sk_buff *skb_frag; + struct libipw_hdr_3addrqos header = {/* Ensure zero initialized */ + .duration_id = 0, + .seq_ctl = 0, + .qos_ctl = 0 + }; + u8 dest[ETH_ALEN], src[ETH_ALEN]; + struct lib80211_crypt_data *crypt; + int priority = skb->priority; + int snapped = 0; + + if (ieee->is_queue_full && (*ieee->is_queue_full) (dev, priority)) + return NETDEV_TX_BUSY; + + spin_lock_irqsave(&ieee->lock, flags); + + /* If there is no driver handler to take the TXB, dont' bother + * creating it... */ + if (!ieee->hard_start_xmit) { + printk(KERN_WARNING "%s: No xmit handler.\n", ieee->dev->name); + goto success; + } + + if (unlikely(skb->len < SNAP_SIZE + sizeof(u16))) { + printk(KERN_WARNING "%s: skb too small (%d).\n", + ieee->dev->name, skb->len); + goto success; + } + + ether_type = ((struct ethhdr *)skb->data)->h_proto; + + crypt = ieee->crypt_info.crypt[ieee->crypt_info.tx_keyidx]; + + encrypt = !(ether_type == htons(ETH_P_PAE) && ieee->ieee802_1x) && + ieee->sec.encrypt; + + host_encrypt = ieee->host_encrypt && encrypt && crypt; + host_encrypt_msdu = ieee->host_encrypt_msdu && encrypt && crypt; + + if (!encrypt && ieee->ieee802_1x && + ieee->drop_unencrypted && ether_type != htons(ETH_P_PAE)) { + dev->stats.tx_dropped++; + goto success; + } + + /* Save source and destination addresses */ + skb_copy_from_linear_data(skb, dest, ETH_ALEN); + skb_copy_from_linear_data_offset(skb, ETH_ALEN, src, ETH_ALEN); + + if (host_encrypt) + fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA | + IEEE80211_FCTL_PROTECTED; + else + fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA; + + if (ieee->iw_mode == IW_MODE_INFRA) { + fc |= IEEE80211_FCTL_TODS; + /* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */ + memcpy(header.addr1, ieee->bssid, ETH_ALEN); + memcpy(header.addr2, src, ETH_ALEN); + memcpy(header.addr3, dest, ETH_ALEN); + } else if (ieee->iw_mode == IW_MODE_ADHOC) { + /* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */ + memcpy(header.addr1, dest, ETH_ALEN); + memcpy(header.addr2, src, ETH_ALEN); + memcpy(header.addr3, ieee->bssid, ETH_ALEN); + } + hdr_len = LIBIPW_3ADDR_LEN; + + if (ieee->is_qos_active && ieee->is_qos_active(dev, skb)) { + fc |= IEEE80211_STYPE_QOS_DATA; + hdr_len += 2; + + skb->priority = libipw_classify(skb); + header.qos_ctl |= cpu_to_le16(skb->priority & LIBIPW_QCTL_TID); + } + header.frame_ctl = cpu_to_le16(fc); + + /* Advance the SKB to the start of the payload */ + skb_pull(skb, sizeof(struct ethhdr)); + + /* Determine total amount of storage required for TXB packets */ + bytes = skb->len + SNAP_SIZE + sizeof(u16); + + /* Encrypt msdu first on the whole data packet. */ + if ((host_encrypt || host_encrypt_msdu) && + crypt && crypt->ops && crypt->ops->encrypt_msdu) { + int res = 0; + int len = bytes + hdr_len + crypt->ops->extra_msdu_prefix_len + + crypt->ops->extra_msdu_postfix_len; + struct sk_buff *skb_new = dev_alloc_skb(len); + + if (unlikely(!skb_new)) + goto failed; + + skb_reserve(skb_new, crypt->ops->extra_msdu_prefix_len); + memcpy(skb_put(skb_new, hdr_len), &header, hdr_len); + snapped = 1; + libipw_copy_snap(skb_put(skb_new, SNAP_SIZE + sizeof(u16)), + ether_type); + skb_copy_from_linear_data(skb, skb_put(skb_new, skb->len), skb->len); + res = crypt->ops->encrypt_msdu(skb_new, hdr_len, crypt->priv); + if (res < 0) { + LIBIPW_ERROR("msdu encryption failed\n"); + dev_kfree_skb_any(skb_new); + goto failed; + } + dev_kfree_skb_any(skb); + skb = skb_new; + bytes += crypt->ops->extra_msdu_prefix_len + + crypt->ops->extra_msdu_postfix_len; + skb_pull(skb, hdr_len); + } + + if (host_encrypt || ieee->host_open_frag) { + /* Determine fragmentation size based on destination (multicast + * and broadcast are not fragmented) */ + if (is_multicast_ether_addr(dest) || + is_broadcast_ether_addr(dest)) + frag_size = MAX_FRAG_THRESHOLD; + else + frag_size = ieee->fts; + + /* Determine amount of payload per fragment. Regardless of if + * this stack is providing the full 802.11 header, one will + * eventually be affixed to this fragment -- so we must account + * for it when determining the amount of payload space. */ + bytes_per_frag = frag_size - hdr_len; + if (ieee->config & + (CFG_LIBIPW_COMPUTE_FCS | CFG_LIBIPW_RESERVE_FCS)) + bytes_per_frag -= LIBIPW_FCS_LEN; + + /* Each fragment may need to have room for encryption + * pre/postfix */ + if (host_encrypt) + bytes_per_frag -= crypt->ops->extra_mpdu_prefix_len + + crypt->ops->extra_mpdu_postfix_len; + + /* Number of fragments is the total + * bytes_per_frag / payload_per_fragment */ + nr_frags = bytes / bytes_per_frag; + bytes_last_frag = bytes % bytes_per_frag; + if (bytes_last_frag) + nr_frags++; + else + bytes_last_frag = bytes_per_frag; + } else { + nr_frags = 1; + bytes_per_frag = bytes_last_frag = bytes; + frag_size = bytes + hdr_len; + } + + rts_required = (frag_size > ieee->rts + && ieee->config & CFG_LIBIPW_RTS); + if (rts_required) + nr_frags++; + + /* When we allocate the TXB we allocate enough space for the reserve + * and full fragment bytes (bytes_per_frag doesn't include prefix, + * postfix, header, FCS, etc.) */ + txb = libipw_alloc_txb(nr_frags, frag_size, + ieee->tx_headroom, GFP_ATOMIC); + if (unlikely(!txb)) { + printk(KERN_WARNING "%s: Could not allocate TXB\n", + ieee->dev->name); + goto failed; + } + txb->encrypted = encrypt; + if (host_encrypt) + txb->payload_size = frag_size * (nr_frags - 1) + + bytes_last_frag; + else + txb->payload_size = bytes; + + if (rts_required) { + skb_frag = txb->fragments[0]; + frag_hdr = + (struct libipw_hdr_3addrqos *)skb_put(skb_frag, hdr_len); + + /* + * Set header frame_ctl to the RTS. + */ + header.frame_ctl = + cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS); + memcpy(frag_hdr, &header, hdr_len); + + /* + * Restore header frame_ctl to the original data setting. + */ + header.frame_ctl = cpu_to_le16(fc); + + if (ieee->config & + (CFG_LIBIPW_COMPUTE_FCS | CFG_LIBIPW_RESERVE_FCS)) + skb_put(skb_frag, 4); + + txb->rts_included = 1; + i = 1; + } else + i = 0; + + for (; i < nr_frags; i++) { + skb_frag = txb->fragments[i]; + + if (host_encrypt) + skb_reserve(skb_frag, + crypt->ops->extra_mpdu_prefix_len); + + frag_hdr = + (struct libipw_hdr_3addrqos *)skb_put(skb_frag, hdr_len); + memcpy(frag_hdr, &header, hdr_len); + + /* If this is not the last fragment, then add the MOREFRAGS + * bit to the frame control */ + if (i != nr_frags - 1) { + frag_hdr->frame_ctl = + cpu_to_le16(fc | IEEE80211_FCTL_MOREFRAGS); + bytes = bytes_per_frag; + } else { + /* The last fragment takes the remaining length */ + bytes = bytes_last_frag; + } + + if (i == 0 && !snapped) { + libipw_copy_snap(skb_put + (skb_frag, SNAP_SIZE + sizeof(u16)), + ether_type); + bytes -= SNAP_SIZE + sizeof(u16); + } + + skb_copy_from_linear_data(skb, skb_put(skb_frag, bytes), bytes); + + /* Advance the SKB... */ + skb_pull(skb, bytes); + + /* Encryption routine will move the header forward in order + * to insert the IV between the header and the payload */ + if (host_encrypt) + libipw_encrypt_fragment(ieee, skb_frag, hdr_len); + + if (ieee->config & + (CFG_LIBIPW_COMPUTE_FCS | CFG_LIBIPW_RESERVE_FCS)) + skb_put(skb_frag, 4); + } + + success: + spin_unlock_irqrestore(&ieee->lock, flags); + + dev_kfree_skb_any(skb); + + if (txb) { + netdev_tx_t ret = (*ieee->hard_start_xmit)(txb, dev, priority); + if (ret == NETDEV_TX_OK) { + dev->stats.tx_packets++; + dev->stats.tx_bytes += txb->payload_size; + return NETDEV_TX_OK; + } + + libipw_txb_free(txb); + } + + return NETDEV_TX_OK; + + failed: + spin_unlock_irqrestore(&ieee->lock, flags); + netif_stop_queue(dev); + dev->stats.tx_errors++; + return NETDEV_TX_BUSY; +} +EXPORT_SYMBOL(libipw_xmit); + +EXPORT_SYMBOL(libipw_txb_free); |